class MyCell: UITableViewCell {
	
	static let identifier: String = "MyCell"
	
	let label = UILabel()
	
	override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
		super.init(style: style, reuseIdentifier: reuseIdentifier)
		commonInit()
	}
	required init?(coder: NSCoder) {
		super.init(coder: coder)
		commonInit()
	}
	private func commonInit() {
		label.translatesAutoresizingMaskIntoConstraints = false
		contentView.addSubview(label)
		let g = contentView.layoutMarginsGuide
		
		let b = label.bottomAnchor.constraint(equalTo: g.bottomAnchor)
		b.priority = .required - 1

		NSLayoutConstraint.activate([
			label.topAnchor.constraint(equalTo: g.topAnchor),
			label.leadingAnchor.constraint(equalTo: g.leadingAnchor),
			label.trailingAnchor.constraint(equalTo: g.trailingAnchor),
			label.heightAnchor.constraint(equalToConstant: 60.0),
			b,
		])
		
		label.font = .systemFont(ofSize: 16.0, weight: .regular)
	}
	
}

class AddRemoveTableViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

	var myData: [String] = []
	var myCounter: Int = 15
	
	let tableView = UITableView()
	
    override func viewDidLoad() {
        super.viewDidLoad()

		tableView.translatesAutoresizingMaskIntoConstraints = false
		view.addSubview(tableView)
		
		let g = view.safeAreaLayoutGuide
		NSLayoutConstraint.activate([
			tableView.topAnchor.constraint(equalTo: g.topAnchor),
			tableView.leadingAnchor.constraint(equalTo: g.leadingAnchor),
			tableView.trailingAnchor.constraint(equalTo: g.trailingAnchor),
			tableView.bottomAnchor.constraint(equalTo: g.bottomAnchor),
		])
		
		myData = (1...myCounter).compactMap( { "Data Item \($0)" } )
		
		navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Insert", style: .plain, target: self, action: #selector(addTapped(_:)))
		
		tableView.register(MyCell.self, forCellReuseIdentifier: MyCell.identifier)
		tableView.dataSource = self
		tableView.delegate = self
		
		let hv = UILabel()
		hv.backgroundColor = .yellow
		hv.text = "Header View"
		hv.frame.size.height = 40.0
		tableView.tableHeaderView = hv
		
		tableView.refreshControl = UIRefreshControl()
		tableView.refreshControl?.addTarget(self, action: #selector(refresh(_:)), for: .valueChanged)
		
		view.backgroundColor = .red
		tableView.backgroundColor = .clear
    }
    
	func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
		return myData.count
	}
	func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
		let c = tableView.dequeueReusableCell(withIdentifier: MyCell.identifier, for: indexPath) as! MyCell
		c.label.text = myData[indexPath.row]
		return c
	}
	
	@objc func addTapped(_ sender: Any?) {
		myCounter += 1
		myData.insert("Inserted Data \(myCounter)", at: 3)
		tableView.insertRows(at: [IndexPath(row: 3, section: 0)], with: .automatic)
	}
	@objc func refresh(_ sender: UIRefreshControl) {
		DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {
			sender.endRefreshing()
		})
	}
	func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
		if editingStyle == .delete {
			myData.remove(at: indexPath.row)
			tableView.deleteRows(at: [indexPath], with: .fade)
		}
	}
	
	func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
		return true
	}
	
	func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCell.EditingStyle {
		return .delete
	}
	
}